I'm getting set to order my 12 yo old sons Christmas present. He really loves shooting my Mark II, so, I thought I would get him a Mark III. Externally they look the same. What differenciates the II from the III except for the additional "I"? Are any design changes negative and I should hit the auction side looking for a Mark II?Can I safely assume the clips will not interchange?

Be aware that the Mark III is exact opposite as far as take down from the other the Mark II. One needs the hammer cocked and one needs the hammer UNCOCKED to put back together. the Magazine release is different"magazines will not interchange". Also the Mark III has the loaded chamber indicator.

The Mark III has a mag release on the side of the receiver, the II has the heel release- I like the III better. The III has a key lock, loaded chamber indicator. Think the II went out of production in 2005, not sure.

"Minds are like parachutes. Just because you've lost yours doesn't mean you can borrow mine."

One other significant difference is the magazine disconnect in the Mk.III. If you go to Rimfire Central and search Mk.III you'll find a lot of discussion about it. There is an easy, and inexpensive fix ($10.00, for a Sam's bushing) if you want to be able to fire the pistol without a magazine in place and want the mags to slide out of the grip frame on their own when you press the release button rather than having to pull them out. I've had all of the variations of Ruger Auto's and love my Mark III 22/45. I did install a Sam's hammer bushing and the loaded chamber indicator doesn't offend me. I may be in the minority on that count. In short, the Mk.III has nothing special that you'll miss in a Mk. II but either will make a great present for your son. Since I'm partial to the .45 style grip frame I really like the new 22/45 with wooden grips. To each his own, said the old lady, as she kissed the cow.

$10.00, out the door. He'll get right back to you and ships same day payment is recvd., though postal arrangements being what they apparantly are between Canada and the U.S. it may take a couple of weeks from the time you send the check. If you visit RimfireCentral you'll find tons of info on the Sam's bushing. I love mine.

Mk II or Buckmark? I'd take a Mk. III with a Sam's bushing over a Buckmark any day, but that's just me. No arguments will be won or lost on this issue. I would only add this:If you have .45 ACP's and/or are a fan of that grip style, then I'd strongly recommend holding one of the new 22/45's with wood grip panels before jumping over to a Browning to spare yourself the trouble of a new bushing and the embarrassment/(hassle?) of an LCI."To each his own", said the old lady as she kissed the cow, eh?